In SGK V2 there are different stances the character can use, Standard, Combat and Aimed. The default key bind to changes stance is CAPS LOCK. When no weapon is equipped the character uses the stance settings set in the BP_PlayerInventory component, you can find these settings in the Class Defaults by searching for stance.
You can use these settings to control the players stance when not holding an item. A stance controls what animations the character will use.
Default Stance – This is the stance the player will start in when the game begins.
Allow Stance Change – If true the player will be able to change stance when not holding an item.
To change the stance settings for when the character is holding an item you need to go to the items holdable bp like for example the BP_M4A4. Then in its Class Defaults you can find the stance settings there for when that item is held.